1. Field of the Invention
The present invention relates to an anisotropically electricity-conductive film having electric conductivity only in the direction of thickness, which is used for the purpose of connecting two circuits opposite to each other by locating the film between these circuits and pressurizing and heating it to thereby allow electrically conductive particles to spread between the circuits, as well as for the purpose of bonding and fixing the circuits by means of an adhesive agent forming the film.
2. Description of the Prior Art
An anisotropically electricity-conductive film is used to form an anisotropically electricity-conductive layer between various terminals and to thereby bond the terminals and, at the same time, electrically connect them. For example, such a film is used to connect a flexible printed circuit board (FPC) or TAB with an ITO terminal formed on a glass substrate in a liquid crystal panel.
Generally, anisotropically electricity-conductive films are composed of an epoxy or phenol resin, a curing agent and electrically conductive particles. Among them, films of one-pack type and thermosetting type have prevailed due to convenience in use or the like. Further, in order to achieve stable bonding reliability even under high temperature and high humidity, improvement of the bonding strength of such a film has been attempted by various methods.
However, conventional anisotropically electricity-conductive films using an epoxy or phenol resin have been low in tackiness and bad in workability.